Temperature control conductive device

ABSTRACT

A passive temperature conductive device for use in mounting flight control units in a missile. The device controls conduction of heat to provide maximum conduction during pre-launch operation from the units and minimum conduction to the units at high altitude flights. The mating surfaces of a conductive joint allows heat to flow freely from the units to the missile skin during pre-launch operation, but restricts the reverse flow of aerodynamic heating into the units during flight.

United States Patent 1191 Stooksberry et al.

Mar. 12, 1974 [5 TEMPERATURE CONTROL CONDUCTIVE DEVICE 1 PrimaryExaminer-Charles Sukalo Attorney, Agent, or Firm-Lawrence A. Neureither;[75] Inventors' g i sgfigi Leonard Flank; Charles R. Carter both ofCalif.

[73] Assignee: The United States of America as [57] ABSTRACT representedby the Secretary of the Army, Washington, DC ,5 A passive temperatureconductive device for use in [22] Filed; May 25, 1972 mounting flightcontrol units in a missile. The device controls conduction of heat toprovide maximum con- [21'] APPl- N04 257,996 duction during pre-launchoperation from the units and minimum conduction to the units at highaltitude [52 U.S. c1. 165/47, 165/80 The mating Surfaces a hductiveJoint 51 1111. C1. F24h 3/00 heat freely fmm the "hits to the missile 58Field of Search 165/47, 80, 185, 186 skin during the-launch Operation,but restricts the verse flow of aerodynamic heating into the units dur-[56] References Cited mg UNITED STATES PATENTS 3 Claims 2 DrawingFigures 3,215,194 11/1965 Sununu et al 165/80 I4 16-5 30 38% AIREVACUATION PATENTEU UAR l 2 I974 fee / IGJ 38 AIR EVACUATION FIG.

Q Q C Q 34% AIR EVACUATION X FIG. 2

TEMPERATURE CONTROL CONDUCTIVE DEVICE BACKGROUND OF THE INVENTION Thisinvention relates to the field of temperature control devices. Missileflight control units are subjected to severe thermal environment duringpre-launch operations which result in heat dissipation problems. Inaddition these units must be capable of sustaining the aerodynamicheating induced during flight. Present designs rely on the addition ofmass .to provide the required heat sink for ground operations and ductsfor cooling air circulation and dissipation of the heat during missileflight.

i SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1shows the temperature control device used in mounting flight controlunits.

FIG. 2 shows a close up view of the mating surfaces of the conductivejoint.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference numeral generallyindicates a heat conducting device for supporting a flight control unit12 by flanges l4 and 16 in a missile 17. The device includes diverginglegs 18 and 20 connected to the missile at points 22 and 24. A resistor26, used for pre-launch testing to provide heat which is representativeof the heat normally produced by internal electrical components 29, ismounted on a plate 28. This plate serves to remove heat from the insideof unit 12. A bolt connects flanges 14 and 16 and the external portionof plate 28 to the device 10. A conductive joint 32 is lo-. cated at thepoint where the mating surfaces of flange 16 and leg 18 meet. Thefinishing of the mating surfaces at the conductive joint combined withthe bolt torque used in securing the elements together provide a uniquestructure for predetermining dissipation of heat during pre-launchtesting and flight of the missile. Variation in either surface finish orbolt torque will vary dissipation of the heat capability of theinvention.

FIG. 2 shows an enlarged view of the mating surfaces of flange l6 andleg 18 at the conductive joint 32. Ref erence numeral 34 identifies themating surface of flange 16 which is end mill finished to a roughness ofV 63 and then anodized. Reference numberal 36 indicates thecorresponding mating surface of leg 18 which is lathe finished to aroughness of V63 and then anod' ized. The tool marks of both surfaces,when mated as shown, intersect at 45 or more and minimizes solid-tosolidconduction due to a space left by the tool marks on the surfaces.Reference numeral 30' schematically identifies the clamping pressureapplied to the mating surfaces by the torque of bolt 30.

During pre flight operation, heat from the flight control unit 12 isconducted through plate 28 and joint 32 to the missile at points 22 and24. These points are separated enough to provide added heat sinkcapability along with adequate structural support.

When the missile is launched it will contain internal trapped air at sealevel pressure. In flight, the missile passes from an outside sea levelpressure to a decaying outside air pressure. Since a missile is notcompletely air tight the trapped air, at sea level pressure, will bleedthrough the missile skin'tending to equalize with the outside airpressure. As air leaves the missile, the inside of the missile isevacuated to a vacuum condition.

This produces a vacuum condition in the voids between the matingsurfaces 34 and 36 which will reduce the thermal conductivity betweenthe surfaces during flight. This technique prevents possibleinterstitial fluid conduction for points not in physical contact. Areduction in the joint thermal conduction by a factor as much as 3 willoccur during flight due to this technique.

The bolt torque which applys the clamping pressure to the matingsurfaces is a predominant factor in the heat conduction. Hence the bolttorque is based on the minimum value to ensure structural integrity.

We claim:

1. A temperature control device for use in a missile to provide maximumheat conduction during prelaunch operation and minimum heat conductionat high altitudes, said device comprising: a flight control unit havinga plate for mounting heat producing electrical components contained insaid flight control unit, said plate provided with a portion extendingoutside of said unit, said unit having an intergal flange with onesurface juxtaposed to said plate, and a machined surface opposite saidplate; a heat conducting device having a pair of divergently connectedlegs, one of said legs. having a machined surface for mating with saidsurface on said flange; both of said surfaces having too] marks disposedto intersect at an angle of at least 45 relative to each other forminimizing surface contact, and bolt means for applying a predeterminedclamping pressure on said mating surfaces.

2. A device as set forth in claim 1 wherein one of said mating surfaceshas a lathe finish and the other surface has an end mill finish, bothsurfaces having a roughness of approximately m and are anodized.

3. A device as set forth in claim 1 wherein said angle of intersectionof said surfaces is greater than 45.

1. A temperature control device for use in a missile to provide maximumheat conduction during pre-launch operation and minimum heat conductionat high altitudes, said device comprising: a flight control unit havinga plate for mounting heat producing electrical components contained insaid flight control unit, said plate provided with a portion extendingoutside of said unit, said unit having an intergal flange with onesurface juxtaposed to said plate, and a machined surface opposite saidplate; a heat conducting device having a pair of divergently connectedlegs, one of said legs having a machined surface for mating with saidsurface on said flange; both of said surfaces having tool marks disposedto intersect at an angle of at least 45* relative to each other forminimizing surface contact, and bolt means for applying a predeterminedclamping pressure on said mating surfaces.
 2. A device as set forth inclaim 1 wherein one of said mating surfaces has a lathe finish and theother surface has an end mill finish, both surfaces having a roughnessof approximately Square Root 63 and are anodized.
 3. A device as setforth in claim 1 wherein said angle of intersection of said surfaces isgreater than 45*.